The present invention relates to a gas filling apparatus and method for a gas shock absorber; and, more particularly, to an apparatus and method capable of filling a gas into a base shell assembly of the gas shock absorber before calking, wherein the apparatus and method eliminate the necessity to punch a hole for filling the gas at a circumference surface of the base shell assembly.
In general, a vehicle has a suspension system so as to block a shock propagating from ground to a vehicle driver and protect a vehicle body.
The suspension system includes a spring and a gas shock absorber, wherein the spring absorbs the shock transferred from the ground and the shock absorber damps vibration generated from the spring, thereby suppressing the expansion of the spring.
As shown in FIG. 1, the gas shock absorber includes a base shell assembly 75, a rod assembly 71, a rod guide 73, and a oil seal 74, wherein the base shell assembly 75 has a cylinder structure; the rod assembly 71 is built inside the base shell assembly in order to perform a reciprocating motion, wherein the inside of the base shell assembly 75 is filled with an oil and a gas.
Meanwhile, the gas filling method in a prior art is as follows.
First of all, a hole for filling gas is formed by punching at a circumference surface of the base shell assembly 75. The oil is poured in a tube assembly and the base shell assembly 75 through the punched hole. Thereafter, the rod assembly 71 is fixed in the tube assembly and the rod guide 73 and the oil seal 74 are combined in the base shell assembly 75 and thereafter top of the base shell assembly 75 is calked by a calking device.
After completely sealing the top of the base shell assembly 75 through the calking device, the gas is filled therein through a gas filling hole. Thereafter, the gas filling hole is completely welded.
The gas filling method in the prior art, however, has an inconvenience in that the extra hole needs to be punched at the circumference surface of the base shell assembly. This has a problem in that the base shell assembly is damaged and the durability thereof is deteriorated.
To solve the problem mentioned above, a gas filling apparatus and method was suggested by the present applicant, wherein an extra hole needs not to be punched at the base shell assembly and gas is filled into the gas shock absorber through a gap located between a rod and a rod guide by using a filling jig and then top portions of the base shell assembly is calked.
However, this had a problem in that either the surface of the rod or the oil seal is damaged while the filling jig is inserted therebetween.
It is, therefore, an object of the present invention to provide a gas filling apparatus and method for the gas shock absorber in which there is no need to punch an extra hole on the base shell assembly and also a rod and an oil seal is not damaged during gas filling process.
In accordance with one aspect of the present invention, there is provided a gas filling apparatus for filling a gas in a base shell assembly of a shock absorber, including: an assembly location correction unit for putting a tube assembly and a rod guide at predetermined positions, respectively, in the base shell assembly by pushing a rod lifted by oil pressure filled in the base shell assembly; and a gas filling unit including a rod chucking unit, a calking jig, an oil seal pushing unit, and a jig housing, wherein the gas filling unit is capable of sealing top of the base shell assembly by calking temporarily after the gas is filled therethrough.
In accordance with another aspect of the present invention, there is provided a gas filling method, including the steps of: correcting an assembly location of a tube assembly and a rod guide in order to fix a position thereof; clamping a base shell assembly transferred to a gas filling unit; lowering the gas filling unit primarily for sealing the top of the base shell assembly by a calking jig; lowering a rod chucking unit for entering a bolt portion of the rod in a collet; lowering a collet housing device for chucking the bolt portion of the rod by the collet; making an oil seal deviate from the top of the base shell assembly, thereby lifting the rod chucking unit; filling a gas between the oil seal and the top of the base shell assembly; lowering the gas filling unit secondarily for inserting the oil seal into the top of the base shell assembly and simultaneously, calking primarily the top of the base shell assembly by a calking projection projected on inside of the calking jig; and calking secondarily the base shell assembly calked primarily, thereafter separating it from the gas filling unit.